<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>

    const xhr = new XMLHttpRequest()
    xhr.open('post', 'http://liulongbin.top:3006/api/addbook')
    // xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded')
    xhr.setRequestHeader('Content-Type', 'application/json')
    xhr.send(JSON.stringify({
      bookname: '聊啊斋',
      author: '施耐庵',
      publisher: '北京图书出版社'
    }))
    xhr.addEventListener('readystatechange', () => {
      if (xhr.readyState === 4 && xhr.status === 200) {
        console.log(xhr.responseText)
      }
    })

  </script>
</body>

</html>